U.S. patent application number 10/780240 was filed with the patent office on 2005-01-20 for ostomy pouches.
Invention is credited to Falconer, Malcolm I..
Application Number | 20050015065 10/780240 |
Document ID | / |
Family ID | 10837219 |
Filed Date | 2005-01-20 |
United States Patent
Application |
20050015065 |
Kind Code |
A1 |
Falconer, Malcolm I. |
January 20, 2005 |
Ostomy pouches
Abstract
An ostomy pouch (10) includes a front wall (12) provided with a
comfort layer (16) and a vent (22). An apertured cover layer (24)
is secured to the front wall (12) through the comfort layer (16) to
define a chamber for a filter element (28) and to provide a smooth
surface to which can be applied an adhesive sticker. The cover
layer (24) includes a plurality of apertures (30), and the flow
rate through the vent can be controlled by positioning the sticker
to selectively block one or more of the apertures (30). An adhesive
wafer (40) includes both circular and non-circular (race-track)
cut-out guidelines for enabling the aperture to be cut to any
desired shape and size. The wafer (40) is secured to the pouch
along a weld line having a shape corresponding to a combined
circular and race-track silhouette.
Inventors: |
Falconer, Malcolm I.; (Clone
West, IE) |
Correspondence
Address: |
BRISTOL-MYERS SQUIBB COMPANY
100 HEADQUARTERS PARK DRIVE
SKILLMAN
NJ
08558
US
|
Family ID: |
10837219 |
Appl. No.: |
10/780240 |
Filed: |
February 17, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10780240 |
Feb 17, 2004 |
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09370305 |
Aug 9, 1999 |
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6709421 |
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Current U.S.
Class: |
604/335 |
Current CPC
Class: |
A61F 2005/4415 20130101;
A61F 2013/51427 20130101; A61F 5/445 20130101; A61F 5/441
20130101 |
Class at
Publication: |
604/335 |
International
Class: |
A61F 005/44 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 13, 1998 |
GB |
9817677.9 |
Claims
What is claimed is:
1. Apparatus comprising a controllable flow rate, filtered, vent
for an ostomy pouch, the vent having a plurality of outlets and a
device for controlling the rate of flow of gas through the vent,
the device comprising adhesive sticker means which can be
positioned and re-positioned to selectively expose or cover one or
more of the plurality of outlets, and thereby regulate variably the
rate of flow of gas according to the outlets exposed.
2. Apparatus according to claim 1, wherein the flow rate is
controllable according to the number of outlets exposed.
3. Apparatus according to claim 1, wherein the sticker means
comprises a sticker dimensioned so that it is of sufficient size to
be able to cover all of the outlets.
4. Apparatus according to claim 1, wherein one or more of the
outlets comprises a hole in a layer to which the sticker means is
adherable.
5. Apparatus according to claim 1, wherein one or more of the
outlets comprises a clearance between one or more outlets, or weld
segments.
6. Apparatus according to claim 1, further comprising a flow
restricting layer provided upstream of the outlets.
7. Apparatus comprising a vent for an ostomy pouch, the vent
comprising aperture means, a flow restricting layer upstream of the
aperture means, and adhesive sticker means which can be positioned
to selectively block one or more areas of the aperture means.
8. Apparatus according to claim 7, wherein the aperture means
comprises a plurality of individual vent apertures.
9. Apparatus according to claim 7, wherein the sticker means
comprises a plurality of stickers or sticker segments.
10. Apparatus according to claim 7, wherein the sticker means is
positioned or positionable to selectively block all of the area of
the aperture means.
11. Apparatus according to claim 7, wherein the flow restricting
layer comprises microporous material.
12. Apparatus according to claim 7, wherein the pouch comprises a
first wall provided with the vent and with a comfort layer.
13. An ostomy pouch comprising a first wall, provided with a
comfort layer and with a flatus vent, the pouch further comprising
adhesive sticker means attached, or attachable, to the vent to
facilitate the control of the flow of flatus through the vent.
14. A pouch according to claim 13, wherein the outlet of the vent
is defined by at least one segment of plastics material positioned
outside the comfort layer, and to which the adhesive sticker means
can adhere.
15. A pouch according to claim 14, wherein said plastics material
has a generally smooth surface to which said sticker means can
adhere.
16. A pouch according to claim 14, wherein said plastics material
is substantially impermeable material.
17. A pouch according to claim 14, wherein said plastics material
overlies a portion of the comfort layer and is secured to the
underlying first wall of the pouch through the comfort layer.
18. A pouch according to claim 14, wherein said plastics material
forms an outer cover over a filter, and is secured to the pouch
wall around the filter.
19. A pouch according to claim 18, wherein the line of attachment
is continuous.
20. A pouch according to claim 18, wherein the line of attachment
is discontinuous to provide a plurality of outlets through which
filtered gas may vent.
21. A pouch according to claim 13, wherein the comfort layer is
provided outside the majority of at least an upper portion of the
pouch.
22. An ostomy pouch comprising a first wall of substantially liquid
impermeable and gas impermeable plastics material, an aperture
provided in the first wall to allow venting of flatus therethrough,
a comfort layer provided outside the first wall, and a filter cover
layer outside the comfort layer and secured to the first wall
through the comfort layer, the cover layer and the portion of the
first wall underlying the cover layer defining a housing in which
is received a filter for processing flatus vented through the
aperture.
23. An ostomy pouch according to claim 22, wherein the cover layer
has a plurality of openings therein to provide a plurality of vent
outlets.
24. An ostomy pouch according to claim 1, further comprising an
adhesive wafer for securing the pouch to a person's skin, wherein
the wafer, or a cover layer provided on the wafer, is provided with
guidelines for enabling a person to cut the wafer to a desired
aperture size, the guidelines including at least one generally
circular guideline and at least one generally non-circular
guideline.
25. An ostomy pouch according to claim 7, further comprising an
adhesive wafer for securing the pouch to a person's skin, wherein
the wafer, or a cover layer provided on the wafer, is provided with
guidelines for enabling a person to cut the wafer to a desired
aperture size, the guidelines including at least one generally
circular guideline and at least one generally non-circular
guideline.
26. An ostomy pouch according to claim 13, further comprising an
adhesive wafer for securing the pouch to a person's skin, wherein
the wafer, or a cover layer provided on the wafer, is provided with
guidelines for enabling a person to cut the wafer to a desired
aperture size, the guidelines including at least one generally
circular guideline and at least one generally non-circular
guideline.
27. An ostomy pouch according to claim 22, further comprising an
adhesive wafer for securing the pouch to a person's skin, wherein
the wafer, or a cover layer provided on the wafer, is provided with
guidelines for enabling a person to cut the wafer to a desired
aperture size, the guidelines including at least one generally
circular guideline and at least one generally non-circular
guideline.
28. An adhesive wafer for directly or indirectly securing an ostomy
pouch to a person's skin, wherein the wafer, or a cover layer
provided on the wafer, is provided with guidelines for enabling a
person to cut the wafer to a desired aperture size, the guidelines
including at least one generally circular guideline, and at least
one generally non-circular guideline.
29. A wafer according to claim 28, wherein the non-circular
guideline or guidelines has or have a race-track shape.
30. A wafer according to claim 28, wherein a plurality of the
circular guidelines and plurality of the non-circular guidelines
are provided.
31. An ostomy pouch comprising a pouch envelope and an adhesive
wafer for directly or indirectly securing the pouch envelope to a
person's skin, wherein the wafer, or a cover layer provided on the
wafer, is provided with guidelines for enabling a person to cut the
wafer to a desired aperture size, the guidelines including at least
one generally circular guideline, and at least one generally
non-circular guideline, and the adhesive wafer being secured to the
envelope around a closed loop line of attachment, the line of
attachment having a shape which is non-circular and
non-race-track.
32. A pouch according to claim 31, wherein the line of attachment
is defined by a combination of a circular shape and a race-track
shape, the combined shape corresponding to a silhouette of one
superimposed on the other.
33. A body-side device for attachment to an ostomy pouch, the
body-side device comprising an adhesive wafer for directly or
indirectly securing the ostomy pouch to a person's skin, and a
coupling portion for releasable fastening to the pouch, wherein the
wafer, or a cover layer provided on the wafer, is provided with
guidelines for enabling a person to cut the wafer to a desired
aperture size, the guidelines including at least one generally
circular guideline, and at least one generally non-circular
guideline, and wherein the wafer is secured to the coupling portion
around a closed loop line of attachment, the line of attachment
having a shape which is non-circular and non-race-track.
34. A device according to claim 33, wherein the line of attachment
is defined by a combination of a circular shape and a race-track
shape, the combined shape corresponding to a silhouette of one
superimposed on the other.
35. Use of adhesive sticker means to control variably the vent flow
rate through a filtered vent for an ostomy pouch, the vent having a
plurality of outlets, and the sticker means being positionable to
selectively expose or cover one or more of the plurality of
outlets, to thereby regulate the gas flow rate according to the
outlets exposed.
36. Use according to claim 35, wherein the flow rate is determined
by the number of outlets exposed.
37. A method of controlling variably the flow rate through a
filtered vent of an ostomy pouch, the method comprising positioning
sticker means to selectively expose or block one or more of a
plurality of outlets of the vent, to regulate the gas flow rate
according to the outlets exposed.
Description
[0001] The present invention relates to ostomy pouches for the
collection of waste, or discharge, from a temporary or permanent
ostomy opening. The invention is applicable equally to so-called
one piece designs in which the pouch is integral with an attachment
pad or wafer for attaching the pouch to the body of the ostomate,
and with so-called two-piece designs in which the pad or wafer for
securing the pouch to the ostomate is separate from, and is
releasably attachable to, the pouch.
[0002] One aspect of the invention relates to a filtered flatus
vent which is commonly provided in certain ostomy pouches. The vent
allows flatus gas within the pouch to escape, in order to avoid
ballooning of the pouch. A sticker is sometimes provided which is
initially adhered over the exit from the vent in order to prevent,
initially, any gas from flowing through the vent. The purpose of
this is, when the pouch is first worn, to allow some gas to build
up within the pouch and thereby prevent the sides of the pouch from
sticking to each other, which could cause undesirable pancaking.
Once the pouch has begun to inflate (and the sides separated from
each other), the sticker can be removed in order to allow flatus to
vent in the normal way.
[0003] In one broad aspect, the invention provides a filtered vent
for an ostomy pouch having a plurality of outlets, and adhesive
sticker means which can be positioned to selectively expose or
cover one or more of the plurality of outlets.
[0004] This aspect can provide a very simple, yet, convenient way
of allowing the user to control the flow rate of flatus passing
through the vent. This is in contrast to the prior art in which the
sticker and the single exit can provide only on/off control. When
the sticker is removed, if the flow rate of gas through the filter
is too high (depending on a particular person's metabolism and on
the food consumed), the sides of the pouch may tend to stick to
each other again, and cause pancaking. However, with this aspect of
the present invention, the ostomate can selectively cover, or
uncover, a desired number of the outlets to control the rate at
which flatus vents, and thereby control the degree of pouch
inflation to prevent pancaking.
[0005] In one embodiment, the sticker means might be dimensioned so
that it is of sufficient size to be able to cover all the outlets
(when positioned appropriately) and can expose one or more of the
exits by being moved to an offset position.
[0006] In an alternative embodiment, the patch means may consist of
a number of separable sticker segments which can be peeled away to
selectively expose one or more exits under each segment.
[0007] In a yet further form, the sticker means may comprise a
plurality of individual stickers each of which can be attached, or
removed, from a respective exit.
[0008] The exits may be in the form of slits, or other apertures,
formed in a plastics film covering, for example, the filter.
Alternatively, the exits may be in the form of clearances between
one or more welds, or weld segments.
[0009] If desired, a flow constricting layer may be provided
upstream of the outlets (for example, under a plastics layer having
outlet apertures). This can allow the apertures to be made larger,
and more easily identifiable, without such critical dependency on
aperture size.
[0010] In a further aspect, the invention provides a vent for an
ostomy pouch, the vent comprising aperture means, a flow
constricting layer upstream of the aperture means, and adhesive
sticker means which can be positioned to selectively block one or
more areas of the aperture means.
[0011] The presence of the flow constricting layer can enable
larger aperture(s) to be used because the flow is constricted by
the layer. The aperture may either be a single aperture (for
example, a relatively large aperture), or a plurality of individual
apertures.
[0012] The flow constricting layer may, for example, consist of
micro-porous material. The layer might, in some embodiments, by
formed by a filter element.
[0013] In a further aspect, the invention relates to an ostomy
pouch having a so-called comfort layer. Such a comfort layer is
generally soft and permeable, and is provided outside the
non-permeable plastics wall of the pouch to provide more
comfortable wearing characteristics. Customers generally prefer a
comfort layer to be provided on both the rear face (i.e. adjacent
to the skin) and on the front face (i.e. facing the wearer's
clothing).
[0014] In this aspect, the invention provides an ostomy pouch in
which a first wall of the pouch is provided with a comfort layer
and with a flatus vent, the pouch further comprising adhesive
sticker means attached, or attachable to the vent to control the
flow of flatus through the vent.
[0015] Preferably, the outlet of the vent is defined by at least
one segment of smooth, substantially impermeable, plastics material
positioned outside the comfort layer. This can provide surface with
excellent characteristics to allow the adhesive sticker means to
adhere to provide a gas-tight. (or at least substantially
gas-tight) seal, and thereby enable the sticker to control the flow
of gas through the vent. To the best of the inventor's knowledge,
it is unknown hitherto to employ a sticker for a vent through a
wall carrying a comfort layer. In particular, it might difficult to
achieve a gas-type seal if the sticker is applied directly to the
comfort layer. In the preferred embodiment, the provision of the
smooth plastics material outside the comfort layer can overcome
this problem.
[0016] As explained previously, there is a need for some form of
device, at least initially, to block or constrict the flow of
flatus through the vent, in order to prevent pancaking. The ability
to provide a simple adhesive sticker means with a comfort-layer
adorned pouch is an extremely significant advantage.
[0017] Preferably, the comfort layer is provided outside the
majority of at least the upper portion of the pouch. Preferably,
the smooth material described above overlies a portion of the
comfort layer, and is secured to the underlying wall of the pouch
through the comfort layer (for example, by welding, or by
adhesive).
[0018] Preferably, the smooth material outside the comfort layer
forms an outer cover for the filter, and is secured to the
underlying pouch wall around the filter. The line of attachment
(e.g. welding) may be continuous, or it may be discontinuous to
provide one or more vent exits.
[0019] In another aspect, the invention relates to the construction
of a filtered vent for an ostomy pouch which has a comfort
layer.
[0020] In this third aspect, the invention broadly provides an
ostomy pouch comprising a first wall of substantially liquid and
gas impermeable plastics material, an aperture being provided in
the first wall to allow the venting of flatus, a comfort layer
provided outside the first wall, and a filter cover layer outside
the comfort layer and secured to the first wall through the comfort
layer, the cover layer and the portion of the first wall underlying
the cover layer defining a housing in which is received a filter
for processing the flatus vented through the aperture.
[0021] The filter may, for example, include material for
deodorising the flatus, and/or material for absorbing any liquid
which accidentally escapes through the aperture in the first
wall.
[0022] The filter may be positioned between the first wall and the
comfort layer. In that case, the filter is preferably attached to
the first wall, to provide a seal around the aperture in the first
wall. Alternatively, the filter may be provided between the comfort
layer and the cover layer. In that case, the filter may either be
attached to the cover layer, or it may be attached to the first
wall.
[0023] A yet further aspect of the invention relates to the
adhesive wafer which is provided conventionally for securing the
pouch to the wearer's skin.
[0024] In accordance with this broad aspect, the wafer (or a cover
layer provided on the wafer) is provided with guidelines for
enabling a person to cut the wafer to a desired aperture size, the
guidelines including at least one generally circular guideline, and
at least one generally non-circular guideline.
[0025] Preferably, the non-circular guideline is a so-called
race-track guideline, defining a shape having generally straight
sides, and rounded ends.
[0026] Preferably, a plurality of circular, and a plurality of
non-circular, guidelines are provided.
[0027] This aspect of the invention can facilitate the same pouch
being usable for a conventional ostomy application (where the
aperture is normally circular) and also for other applications,
including temporary ostomy (for example, loop ostomy) applications.
For a temporary ostomy application, a more elongate aperture is
desired to accommodate a temporary fold in the ostomate's
intestines.
[0028] To the best of the inventor's knowledge, hitherto pouches
have only been available exclusively with circular guidelines, or
exclusively with race-track guidelines. This has meant that a
specific pouch has to be obtained to suit the desired application.
However, with the present invention, a single pouch can be provided
which a user can adapt very easily to the correct circular, or
non-circular aperture size.
[0029] This aspect of the invention can be used either in a
one-piece pouch design, or in a two-piece pouch design. Especially
(but not exclusively) for the one-piece design, it is preferred
that the wafer is secured to the pouch (or pouch coupling member)
by means of a weld or glue line having a non-circular and
non-race-track shape. Preferably, the shape is defined by a
combination of a circular shape and a race-track shape, the shape
corresponding to a silhouette of one superimposed on the other.
[0030] The use of such a weld (or glue) line might be the most
efficient shape for accommodating a large circular, or race-track
cut out, without requiring the adhesive wafer to be unnecessarily
large.
[0031] Preferably, the wafer also has a "hybrid" outer shape based
generally on the silhouette of a circular shape and a race-track
shape superimposed one on the other.
[0032] It will be appreciated that the guidelines might be provided
(by printing) directly on the adhesive wafer, or they may be
provided on a release sheet which protects the adhesive surface of
the wafer before use. The release sheet is intended to be peeled
away before the adhesive wafer is pressed against the skin.
[0033] Although the above aspects may be used independently of each
other, further benefits can arise by combining two or more of the
above aspects in combination. The invention contemplates that any
of the above aspects may be used in combination.
[0034] Embodiments of the invention are now described, by way of
example only, with reference to the accompanying drawings, in
which:
[0035] FIG. 1 is a sectional through a first embodiment of an
ostomy pouch;
[0036] FIG. 2 is a schematic exploded view showing the construction
of the filter and filter housing
[0037] FIGS. 3a-3e are schematic plan views showing adjustment of
the sticker for flow control;
[0038] FIG. 4 is a rear view of the pouch of FIG. 1;
[0039] FIGS. 5a and 5b illustrate different cut outs of aperture in
the wafer shown in FIG. 4;
[0040] FIG. 6 illustrates a modified pouch and wafer with a
mechanical coupling;
[0041] FIGS. 7a and 7b are schematic views showing a modified
design of filter cover;
[0042] FIGS. 8a and 8b illustrate an alternative construction of
filter;
[0043] FIGS. 9a and 9b illustrate a yet further construction of
filter;
[0044] FIGS. 10a-10d illustrate schematically positioning of the
sticker for controlling the flow through the filter of FIGS. 9a and
9b;
[0045] FIGS. 11a and 11b illustrate a further modified design of
filter;
[0046] FIGS. 12a-12e illustrate schematically peeling of the
sticker for controlling the flow through the filter of FIGS. 11a
and 11b.
[0047] Referring to FIGS. 1-5, and ostomy pouch 10 includes an
envelope formed by a frontwall 12 and a rear wall 14 both of
plastics material which is substantially impervious to liquid and
to gas. Such plastics materials are well known in the art, and
typically may consist of a laminate of one or more layers of
ethylene vinyl acetate (EVA) on either side of a barrier layer of
polyvinylidine chloride (PVDC). Other materials may be used as
desired.
[0048] A front comfort layer 16 is positioned outside the front
wall 12, and a rear comfort layer 18 is positioned outside the rear
wall 14. The comfort layers are generally soft and are permeable to
gas and to liquid. Typically the comfort layers are made of Nylon,
or polyethylene, or a mixture of polyester, viscous and rayon.
[0049] The front and rear walls 12 and 14 and the comfort layers 16
and 18 are secured to each other by welding around a peripheral
seam 20. The welding may be performed by an RF welding head, for
example. Alternatively the seam may be formed by impulse welding,
or by a heat seal and cut process.
[0050] A filter housing 22 is located towards an upper portion of
the front wall 12. The housing is formed by a filter cover 24 which
is secured through the front comfort layer 16 to the front wall 12
in a generally gas-tight manner. In the present embodiment, the
filter cover 24 is attached by welding, and the heat generated by
welding is sufficient to at least partly melt the comfort layer in
order to perform a reliable seal between the filter cover 24 and
the front wall 12. The filter cover may, for example, be made of
the same material as the front and rear walls 12 and 14.
[0051] An aperture 26 is formed in the front wall 12 under the
filter cover 24, and a filter element 28 is secured to the front
wall 12 over the aperture 26. In this embodiment, the filter is a
deodorising filter for deodorising flatus gas, and includes a
deodorising agent, such as carbon. The filter may consist of foam
carrying the carbon, or it may consist of other material, such as
charcoal cloth. If desired, the filter may also include additional
agents, such as a super absorbent agent for absorbing any liquid
which leaks accidentally through the aperture 26.
[0052] A suitable deodorising filter is manufactured by Freudenberg
Limited, for example under the reference "option 20".
[0053] Although the filter is illustrated to lie between the front
wall 12 and front comfort layer 16, it will be appreciated that in
other embodiments, the filter could be positioned between the
filter cover 24 and the comfort layer 16, or on the other side of
the front wall 12 (i.e. inside the envelope). The filter would need
to be sealed to at least one of the front wall 12 and the filter
cover 24, in order to prevent flatus leaking around the outside of
the filter element 28.
[0054] A plurality of gas exits 30 are formed in the filter cover
24. In the preferred embodiment, the exits 30 are relatively small
(pin-hole) apertures in the filter cover 24. The number of
apertures may be varied as desired; in the present embodiment, four
apertures are illustrated.
[0055] One or more of the apertures 30 may be selectively blocked
by means of an adhesive sticker 32. As best seen in FIG. 3 the
sticker consists of a main circular portion 34, and a finger tab 36
to enable the sticker to be grasped and peeled from the surface of
the filter cover 24.
[0056] The combination of the plurality of apertures 30 and the
sticker 32 enables the user to control the rate of the flow of gas
through the vent and the filter. As best seen in FIG. 3a, the size
of the main circular portion 34 is sufficient to enable the
sticker, when positioned appropriately, to block all four of the
apertures 30. This completely cuts off flow through the filter
vent.
[0057] As illustrated in FIGS. 3b-3e, by positioning the sticker 30
appropriately, 1, 2, 3 or all 4 of the apertures 30 may be exposed
to allow a progressive increase in the flow rate through the filter
vent. Such use of the sticker can provide the user with an
extremely powerful, yet easy to use, flow control.
[0058] Moreover, it will be appreciated that the use of material
(in this case the filter cover 24) outside the front comfort layer
16 enables a sticker to be applied to achieve a substantially gas
tight sticker seal. The sticker might be virtually ineffective if
it were applied directly to the porous comfort layer.
[0059] Referring to FIGS. 1 and 4, the rear wall 14 and the rear
comfort layer 18 include a stoma aperture 38 for receiving the
ostomate's stoma, and for allowing the stomal discharge into the
envelope. Attached to the rear wall 14, and encircling the stomal
aperture 38 is an adhesive wafer 40 for allowing the pouch to be
secured to the ostomate's skin.
[0060] The wafer 40 consists generally of a layer of
skin-compatible adhesive 42, a backing layer 44 of plastics
material welded to the rear wall 14, and a silicone release sheet
46 having a finger tab 48 by which the release shut 46 can be
peeled away from the adhesive 42 to expose the adhesive face. As
best seen in FIG. 4, the release sheet 46 is printed with
guidelines 50, (50a and 50b) for enabling the user to cut the wafer
to a desired aperture size prior to fitting. This may either be
carried out by the ostomate, or by a supervising nurse or other
medical practitioner.
[0061] In this embodiment, the guidelines include circular
guidelines 50a and non-circular (race track) guidelines 50b. The
circular guidelines 50a define a range of circular shaped apertures
of different sizes, to suite permanent stomas, which generally have
a circular or near-circular configuration. The race track
guidelines 50b define a number of elongate apertures of different
sizes, suitable for temporary stomas (e.g. stomas formed in a
loop-ostomy operation, in which a portion of the intestine is
extracted and is folded around a suitable rod, and is "sliced" open
to define an elongate temporary stoma).
[0062] As mentioned above, the backing layer 44 is welded to the
rear wall 14. The weld line is illustrated in FIG. 4 by the shaded
region 52. The weld line 52 defines a shape which is a silhouette
of a circular shape superimposed on a race track shape. On this
embodiment, the weld line 52 corresponds to the silhouette
surrounding the largest permissible circular cut out, and the
largest permissible race track cut out. The use of such a special
shape of weld line 52 can provide a more versatile pouch design,
enabling large circular cut outs (e.g. see FIG. 5a), and large race
track cut outs (e.g. see FIG. 5b), to be accommodated without
unnecessarily increasing the size of the wafer, or the size of the
weld line between the wafer 40 and the pouch 10.
[0063] As illustrated in FIG. 4, the overall shape of the wafer 40
is similar to the shape of the weld line 52, and corresponds to the
silhouette of a circular shape superimposed on a racetrack
shape.
[0064] Although the above embodiment is a one-piece pouch, it will
be appreciated that the same principles could be applied to a
two-piece pouch (FIG. 6) in which the adhesive wafer 40 is not
permanently fixed to the remainder of the pouch, but is a separate
element 58 which is releasably attachable to the pouch, for
example, by a mechanical coupling, or an adhesive coupling. Such
couplings are well known in the art, and need not be described
further here.
[0065] FIGS. 7a and 7b illustrate, in one form, the relationship
between the size of apertures in the filter cover 24, and the need
for the apertures to provide a constriction to the flow rate. It
will be appreciated that, in order to achieve an adjustable flow,
each individual aperture must provide a constriction to the flow of
flatus gas. This can be achieved by making the apertures 30
suitably small, for example, in the form of slits (FIG. 7a).
Alternatively, a flow constricting layer 60 may be provided under
the filter cover 24 to constrict the flow through each aperture 30.
This would allow the use of much large apertures 30, making them
easier to identify than if narrow slits were to be used. A suitable
constriction layer is of microporous material.
[0066] FIGS. 8a and 8b illustrate a modified construction of filter
without the presence of a comfort layer. In this embodiment, the
filter element 28 is located inside the envelope, on the inside
face of the front wall 12. The aperture 26 in the front wall 12 is
typically about 8-10 mm in diameter. To allow the use to control
the flow with a sticker, the filter cover 24 (now referred to
simply as a outer cover 24) is attached to the outer face of the
front wall 12, and is provided with small pin-holes 30. The size of
each pin-hole 30 is sufficiently small to constrict the flow of
flatus through the apertures when one or more of the apertures is
covered by the sticker 32. If desired, a constriction layer (not
shown) similar to the constriction layer 60, may be provided under
the cover layer 24 if larger, more easily identifiable, apertures
30 are required.
[0067] In this embodiment, since the filter element 28 is located
inside the envelope, it is preferred that a semi-porous protective
membrane, or curtain, 62 be provided over the inner face of the
filter, to prevent faecal matter in the pouch from directly
contacting the filter element 28.
[0068] FIGS. 9a and 9b illustrate a further modified embodiment in
which the filter element 28 is located outside the front wall 12 of
the pouch. The cover layer 24 has three relatively large apertures
30 which are arranged in a generally straight line. A constriction
layer 62 (micro-porous membrane) is located under the cover layer
24, in order to provide the required flow constriction for the size
of aperture. Since the apertures 30 are arranged in a line, the
constriction layer 62 is provided in the form of a narrow strip, in
order to reduce wastage of material.
[0069] FIGS. 10a-10b illustrate the various positions of the
sticker 32 over the apertures 30, to vary the flow from zero (FIG.
10a) to full flow (FIG. 10d).
[0070] FIGS. 11a and 11b illustrate a yet further modified
construction of filter housing. In contrast to the earlier
embodiments in which the cover layer 24 is sealed completely around
the filter element 28 and has apertures 30 through the cover layer
24, the present embodiment employs a completely impervious cover
layer 64, and the vent exits are defined by gaps 66 between weld
segments 68 securing the cover 24 to the front wall 12 of the
pouch. In the present embodiment, the cover 24 is illustrated to
have a rounded end 70 to match the contour around the filter and a
square end 72 at which the gas exits 66 are defined.
[0071] FIGS. 12a-12e illustrate how the flow rate through the exits
66 can be controlled by means of a sticker 74. Although a single
sticker could be used as in the previous embodiments, here a
multiple-segment sticker 74 consisting of segments 76 is employed.
The flow rate is controlled by peeling away individual segments 76
from the exits 66. The segments may be separate from each other, or
they may be attached to each other by breakable perforations 78 to
allow the segments to be torn away.
[0072] Although the embodiments illustrated in FIGS. 8-12 do not
include a comfort layer, it will be appreciated that the
embodiments may be modified to include a comfort layer using the
same principles as described in the first embodiment.
[0073] It will be appreciated that many modifications of detail may
be made without departing from the scope and principals of the
invention. Although features believed to be of particular
importance are defined in the appended claims, the applicant claims
protection for any novel feature or idea described herein and/or
illustrated in the drawings whether or not emphasis has been placed
thereon.
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